支持断点续传的PHP 下载远程文件类

PHP 下载远程文件类,支持断点续传下载，代码内含有具体的调用说明。程序主要是使用 HTTP 协议下载文件，HTTP1.1协议必须指定文档结束后关闭链接,否则读取文档时无法使用feof判断结束，可以有两种使用方法，具体请下载查看源码。

1. /**
2. * 下载远程文件类支持断点续传
3. */
4. class HttpDownload {
5. private $m_url = "";
6. private $m_urlpath = "";
7. private $m_scheme = "http";
8. private $m_host = "";
9. private $m_port = "80";
10. private $m_user = "";
11. private $m_pass = "";
12. private $m_path = "/";
13. private $m_query = "";
14. private $m_fp = "";
15. private $m_error = "";
16. private $m_httphead = "" ;
17. private $m_html = "";
19. /**
20. * 初始化
21. */
22. public function PrivateInit($url){
23. $urls = "";
24. $urls = @parse_url($url);
25. $this->m_url = $url;
26. if(is_array($urls)) {
27. $this->m_host = $urls["host"];
28. if(!empty($urls["scheme"])) $this->m_scheme = $urls["scheme"];
29. if(!empty($urls["user"])) $this->m_user = $urls["user"];
30. if(!empty($urls["pass"])) $this->m_pass = $urls["pass"];
31. if(!empty($urls["port"])) $this->m_port = $urls["port"];
32. if(!empty($urls["path"])) $this->m_path = $urls["path"];
33. $this->m_urlpath = $this->m_path;
34. if(!empty($urls["query"])) {
35. $this->m_query = $urls["query"];
36. $this->m_urlpath .= "?".$this->m_query;
37. }
38. }
39. }
41. /**
42. * 打开指定网址
43. */
44. function OpenUrl($url) {
45. #重设各参数
46. $this->m_url = "";
47. $this->m_urlpath = "";
48. $this->m_scheme = "http";
49. $this->m_host = "";
50. $this->m_port = "80";
51. $this->m_user = "";
52. $this->m_pass = "";
53. $this->m_path = "/";
54. $this->m_query = "";
55. $this->m_error = "";
56. $this->m_httphead = "" ;
57. $this->m_html = "";
58. $this->Close();
59. #初始化系统
60. $this->PrivateInit($url);
61. $this->PrivateStartSession();
62. }
64. /**
65. * 获得某操作错误的原因
66. */
67. public function printError() {
68. echo "错误信息：".$this->m_error;
69. echo "具体返回头：
    ";
70. foreach($this->m_httphead as $k=>$v) {
71. echo "$k => $v
    \r\n";
72. }
73. }
75. /**
76. * 判别用Get方法发送的头的应答结果是否正确
77. */
78. public function IsGetOK() {
79. if( ereg("^2",$this->GetHead("http-state")) ) {
80. return true;
81. } else {
82. $this->m_error .= $this->GetHead("http-state")." - ".$this->GetHead("http-describe")."
    ";
83. return false;
84. }
85. }
87. /**
88. * 看看返回的网页是否是text类型
89. */
90. public function IsText() {
91. if (ereg("^2",$this->GetHead("http-state")) && eregi("^text",$this->GetHead("content-type"))) {
92. return true;
93. } else {
94. $this->m_error .= "内容为非文本类型
    ";
95. return false;
96. }
97. }
98. /**
99. * 判断返回的网页是否是特定的类型
100. */
101. public function IsContentType($ctype) {
102. if (ereg("^2",$this->GetHead("http-state")) && $this->GetHead("content-type") == strtolower($ctype)) {
103. return true;
104. } else {
105. $this->m_error .= "类型不对 ".$this->GetHead("content-type")."
     ";
106. return false;
107. }
108. }
110. /**
111. * 用 HTTP 协议下载文件
112. */
113. public function SaveToBin($savefilename) {
114. if (!$this->IsGetOK()) return false;
115. if (@feof($this->m_fp)) {
116. $this->m_error = "连接已经关闭！";
117. return false;
118. }
119. $fp = fopen($savefilename,"w") or die("写入文件 $savefilename 失败！");
120. while (!feof($this->m_fp)) {
121. @fwrite($fp,fgets($this->m_fp,256));
122. }
123. @fclose($this->m_fp);
124. return true;
125. }
127. /**
128. * 保存网页内容为 Text 文件
129. */
130. public function SaveToText($savefilename) {
131. if ($this->IsText()) {
132. $this->SaveBinFile($savefilename);
133. } else {
134. return "";
135. }
136. }
138. /**
139. * 用 HTTP 协议获得一个网页的内容
140. */
141. public function GetHtml() {
142. if (!$this->IsText()) return "";
143. if ($this->m_html!="") return $this->m_html;
144. if (!$this->m_fp||@feof($this->m_fp)) return "";
145. while(!feof($this->m_fp)) {
146. $this->m_html .= fgets($this->m_fp,256);
147. }
148. @fclose($this->m_fp);
149. return $this->m_html;
150. }
152. /**
153. * 开始 HTTP 会话
154. */
155. public function PrivateStartSession() {
156. if (!$this->PrivateOpenHost()) {
157. $this->m_error .= "打开远程主机出错!";
158. return false;
159. }
160. if ($this->GetHead("http-edition")=="HTTP/1.1") {
161. $httpv = "HTTP/1.1";
162. } else {
163. $httpv = "HTTP/1.0";
164. }
165. fputs($this->m_fp,"GET ".$this->m_urlpath." $httpv\r\n");
166. fputs($this->m_fp,"Host: ".$this->m_host."\r\n");
167. fputs($this->m_fp,"Accept: */*\r\n");
168. fputs($this->m_fp,"User-Agent: Mozilla/4.0+(compatible;+MSIE+6.0;+Windows+NT+5.2)\r\n");
169. #HTTP1.1协议必须指定文档结束后关闭链接,否则读取文档时无法使用feof判断结束
170. if ($httpv=="HTTP/1.1") {
171. fputs($this->m_fp,"Connection: Close\r\n\r\n");
172. } else {
173. fputs($this->m_fp,"\r\n");
174. }
175. $httpstas = fgets($this->m_fp,256);
176. $httpstas = split(" ",$httpstas);
177. $this->m_httphead["http-edition"] = trim($httpstas[0]);
178. $this->m_httphead["http-state"] = trim($httpstas[1]);
179. $this->m_httphead["http-describe"] = "";
180. for ($i=2;$i $this->m_httphead["http-describe"] .= " ".trim($httpstas[$i]);
181. }
182. while (!feof($this->m_fp)) {
183. $line = str_replace("\"","",trim(fgets($this->m_fp,256)));
184. if($line == "") break;
185. if (ereg(":",$line)) {
186. $lines = split(":",$line);
187. $this->m_httphead[strtolower(trim($lines[0]))] = trim($lines[1]);
188. }
189. }
190. }
192. /**
193. * 获得一个Http头的值
194. */
195. public function GetHead($headname) {
196. $headname = strtolower($headname);
197. if (isset($this->m_httphead[$headname])) {
198. return $this->m_httphead[$headname];
199. } else {
200. return "";
201. }
202. }
204. /**
205. * 打开连接
206. */
207. public function PrivateOpenHost() {
208. if ($this->m_host=="") return false;
209. $this->m_fp = @fsockopen($this->m_host, $this->m_port, &$errno, &$errstr,10);
210. if (!$this->m_fp){
211. $this->m_error = $errstr;
212. return false;
213. } else {
214. return true;
215. }
216. }
218. /**
219. * 关闭连接
220. */
221. public function Close(){
222. @fclose($this->m_fp);
223. }
224. }
226. #两种使用方法，分别如下：
228. #打开网页
229. $httpdown = new HttpDownload();
230. $httpdown->OpenUrl("http://www.google.com.hk");
231. echo $httpdown->GetHtml();
232. $httpdown->Close();
234. #下载文件
235. $file = new HttpDownload(); # 实例化类
236. $file->OpenUrl("http://www.ti.com.cn/cn/lit/an/rust020/rust020.pdf"); # 远程文件地址
237. $file->SaveToBin("rust020.pdf"); # 保存路径及文件名
238. $file->Close(); # 释放资源
239. ?>

复制代码

断点续传, PHP